The present disclosure relates to reactors that are utilized as component parts of power conversion devices such as onboard DC-DC converters to be installed in vehicles such as hybrid automobiles and the like. In particular, the present disclosure relates to reactors capable of holding sensors, which are utilized for measurement of physical quantities (temperature, electric current and the like) during operation of the reactors, at suitable positions.
A reactor is employed as a part of a circuit for boosting or stepping down an electric voltage. For example, JP 2010-245458A discloses a reactor utilized for converters installed in vehicles such as hybrid automobiles. The reactor is provided with a coil having a pair of coil elements, an annular magnetic core in which the coil is disposed and which constitutes a closed magnetic path, a case accommodating an assembly of the coil and the magnetic core, and an encapsulating resin (secondary resin portion, potting resin) filled within the case.
When the coil is heated by electrical connection, a loss of the reactor is increased by the heat generation. The reactor is generally used after fixing it to an object to which it is to be installed, such as a cooling base for cooling the coil. It is conceivable that, while the reactor is utilized, a sensor for measurement of a physical quantity such as temperature or electric current of the coil is disposed in proximity to the reactor, for the purpose of controlling the electric current flowing to the coil according to the measured temperature and the electric current.
JP 2010-245458A discloses a reactor, in which a sensor is disposed between coil elements in a direction perpendicular to both of the direction in which the two coil elements are lined up and the axial direction of the coil elements. JP 2012-191172A discloses a reactor in which each coil element has an end surface shaped to have rounded corner portions with rounded corners, and a sensor is disposed in a trapezoidal shaped space which is interposed between the rounded corner portions of the coil elements and extends along an axial direction of the coil. This reactor is provided with an insulator interposed between the coil and a magnetic core. The insulator is unified to a sensor holding portion which presses a temperature sensor towards the coil side.